Computer model analysis is an integral part of the space station Environmental Control and Life Support System (ECLSS) development program. Systems level computer models are being developed to address key parameters in the design of the Air Revitalization (AR), Temperature and Humidity Control (THC), and Atmosphere Control and Supply (ACS) subsystems of the space station ECLSS. The models are being used to resolve design issues related to appropriate control methodology, flow distribution schemes, and optimum sequencing of the AR, THC, and ACS components. The Computer Aided Systems Engineering and Analysis (CASE/A) program, in continuing development at the Marshall Space Flight Center (MSFC), is being used to develop these models. Data made available through hardware testing at the MSFC Core Module Integration Facility (CMIF) was used extensively during verification of these models. This paper describes the build-up and verification of a model used for the design and analysis of the current space station ECLSS configuration, discusses the results generated to date, and outlines plans for future analytical efforts.